Airplanes fly on an amazingly simple principle - when air flows over the wing, it creates lift. It's an astonishing thing. The engine that powered the Wright Brothers' plane had only 25 horsepower, but it got that homemade vehicle going fast enough that airflow over the wings created lift, and, well, the rest is history.

We all want to take flight, don't we? We want to soar through life, get stuff done, and when everything's aligned, it seems you can do just that. When you're soaring, you have that 20,000 foot view of things, decisions seem obvious and it all takes surprising little effort.

But helicopters fly, too, don't they? Yes, but they don't soar. If an airplane is a engineering marvel of harnessing natural forces, the helicopter is a brute force device to accomplish nearly the same thing. Rather than nudging an aerodynamic design forward to initiate elegant physics, the helicopter is dependent upon constant horsepower to keep off the ground. The same principles of lift apply, but they get no assist from an airfoil - every turn of the rotors is required to keep the craft aloft. If the power stops, even for an instant, the copter drops like a stone.

So, some days, yes, you get to soar, and with a minimal amount of effort, handle everything life puts in front of you. Challenges are no more than a cooling breeze on your face as you fly along. You're Superman!

Other days, you're a Sikorsky. Ungainly, still capable, still effective, but every inch forward is a result of pure determination, will and horsepower. You can't find any momentum - you let up a little bit and you plummet back to Earth.

This applies to my music playing. There are days when I play effortlessly, from the heart, and I donít even have to think about it. I can play beyond my abilities on days like that. It applies to singing, too. There are days when my range is barely a formality. I need to sing a note, I sing the note Ė whatís the big deal? Those airplane days, those times in the zone, well, thereís no drug quite like it. Once youíve felt that feeling, you chase it the rest of your days.

Other times, itís like Iím wearing oven mitts and my throatís full of sand. I have to struggle any kind of music whatsoever. Thereís no sense of momentum. Notes donít flow - each one must be laboriously planned and meticulously reached (if youíre lucky). Generally, having played as long as I have, I can power through these days, but thereís little joy to it. Itís a slog.